Modes of Operation

Server

In VTP server mode, you can create, modify, and delete VLANs and specify other configuration parameters (such as VTP version and VTP pruning) for the entire VTP domain. VTP servers advertise their VLAN configuration to other switches in the same VTP domain and synchronize their VLAN configuration with other switches based on advertisements received over trunk links. VTP server is the default mode.

Transparent

VTP transparent switches do not participate in VTP. A VTP transparent switch does not advertise its VLAN configuration and does not synchronize its VLAN configuration based on received advertisements. However, in VTP version 2, transparent switches do forward VTP advertisements that they receive out their trunk ports.

Client

VTP clients behave the same way as VTP servers, but you cannot create, change, or delete VLANs on a VTP client.

Advertisements Summary Advertisements

When the switch receives a summary advertisement packet, it compares the VTP domainname to its own VTP domain name. If the name is different, the switch simply ignores the packet. If the name is the same, the switch then compares the configuration revision to its own revision. If its own configuration revision is higher or equal, the packet is ignored. If it is lower, an advertisement request is sent.

Subset Advertisements

When you add, delete, or change a VLAN in a switch, the server switch where the changes were made increments the configuration revision and issues a summary advertisement, followed by one or several subset advertisements. A subset advertisement contains a list of VLAN information. If there are several VLANS, more than one subset advertisement may be required in order to advertise them all.

Advertisement Requests

A switch needs a VTP advertisement request in the following situations:

The switch has been reset. The VTP domain name has been changed. The switch has received a VTP summary advertisement with a higher configuration revision than its own. Upon receipt of an advertisement request, a VTP device sends a summary advertisement, followed by one or more subset advertisements.

Configuration To configure an IOS based switch to be a VTP server, issue the following commands:

SwitchA# vlan database

SwitchA(vlan)# exit

These commands configure the switch to be a VTP server in the VTP domain CiscoKits. The changes are saved and the revision number is incremented when the exit command is issued. To configure a VTP client, run the following commands:

SwitchB# vlan database

SwitchB(vlan)# exit

To disable VTP, set the vtp mode to transparent as such:

SwitchC# vlan database

SwitchC(vlan)# exit

To monitor the VTP operation and status, use either:

SwitchA# show vtp status

or

SwitchA# show vtp counters.

802.1X Operation

A network switch acts as the middleman between an authenticating client and an authentication server. The switch implements two protocols: EAP is used to communicate with the client at the network perimeter, while RADIUS is used to relay authentication details to the server inside the network. EAP offers a number of authentication mechanisms, but our setup will use simple username/password authentication with an MD5 challenge. The flow of a successful authentication is illustrated here:

For a better idea of what this exchange looks like on the wire, check out these packet captures of 802.1X and RADIUS traffic.
Server Configuration

For my setup, I chose to install FreeRADIUS on my Gentoo Linux workstation, but any RADIUS service should work. The configurations in this section correspond to a bare FreeRADIUS deployment using cleartext credentials stored in a text file. Obviously, real-world deployments would dictate a much more robust and secure authentication method such as LDAP.

The base server configuration is located in radiusd.conf (on Linux, this file should reside in /etc/raddb/), but we shouldn’t need to change any of the default values for this lab. However, we will need to add the subnet address from which we expect to receive authentication requests (10.0.0.0/24) in clients.conf. Remember that although the 802.1X client resides in VLAN 10, the RADIUS client (the switch) will be sending requests from its 10.0.0.1 interface. Copy and paste this block to enable the network with the shared secret of MyRadiusKey:

client 10.0.0.0/24 {
secret = MyRadiusKey
shortname = Lab
}

We’ll also define a user/password combination for testing. I’ve created the user John.McGuirk with the password S0cc3r. Feel free to pick your own username and password, but make sure to maintain the spacing in the configuration file (the reply message is optional):

John.McGuirk Cleartext-Password := “S0cc3r”
Reply-Message = “Hello, %u”

After completing this configuration remember to (re)start the RADIUS service.
Switch Configuration

Port-based 802.1X authentication allows for some really cool security measures (like dynamic VLAN assignment and per-user ACLs), but for this lab we’ll establish a base configuration just for demonstration’s sake.

A preliminary step, if you haven’t done so already, is to enable IP routing on the switch:

Switch(config)# ip routing

Before diving into the actual 802.1X configuration, we’ll need to enable Authentication, Authorization, and Accounting (AAA) for the switch (this step can be skipped if AAA is already active). A word of caution: enabling AAA changes the authentication method used by the VTY (telnet) lines to fit the AAA model. It’s a good idea to define a local username and password to authenticate to the switch if you haven’t done so (this account is unrelated to our 802.1X configuration, just a way for us to log in again if we need to).

Switch(config)# aaa new-model
Switch(config)# username admin secret MyPassword

Next we’ll configure the switch with the address and shared key of our RADIUS server. By default, Cisco switches will use UDP port 1645 for RADIUS authentication and port 1646 for accounting. Depending on the RADIUS daemon you chose to implement, you may need to modify these ports to match those used by your RADIUS daemon. FreeRADIUS, for example, uses the more recent port specification defined in RFC 2138, and requires additional configuration on the switch to reflect the port changes:

Switch(config)# radius-server host 10.0.0.100 auth-port 1812 acct-port 1813 key MyRadiusKey

Now we’ll tie these two components together by configuring AAA to reference the RADIUS server for 802.1X authentication requests:

Switch(config)# aaa authentication dot1x default group radius

This takes care of the RADIUS portion of the configuration. Configuring 802.1X from this point is simple: enable it globally for the switch, and individually per interface:

Switch(config)# dot1x system-auth-control
Switch(config)# interface g0/12
Switch(config-if)# switchport mode access
Switch(config-if)# dot1x port-control auto

Note that the interface must be set to static access mode. If left in dynamic mode (where DTP is used to negotiate the port’s function as either access or trunking), the switch will issue an error message stating that 802.1X cannot be configured on dynamic ports.

If you’re inquisitive like me and issue a question mark to invoke the context-sensitive help in the midst of issuing a new command, you might have noticed that the dot1x port-control interface command has three options. These are:

auto – Normal 802.1X authentication
force-authorized – No 802.1X authentication is used (this is the default setting, to prevent service interruption while deploying 802.1X)
force-unauthorized – Ignores authentication attempts, port is always unauthorized

You can use the show dot1x command to verify the configuration of your client-facing interface:

Switch# show dot1x interface g0/12
Supplicant MAC
AuthSM State = N/A
BendSM State = N/A
PortStatus = N/A
MaxReq = 2
MaxAuthReq = 2
HostMode = Single
PortControl = Auto
QuietPeriod = 60 Seconds
Re-authentication = Disabled
ReAuthPeriod = 3600 Seconds
ServerTimeout = 30 Seconds
SuppTimeout = 30 Seconds
TxPeriod = 30 Seconds
Guest-Vlan = 0

Client Configuration

The last element to configure is the supplicant software on the client. If your client is currently connected, unplug it temporarily before continuing (reconnecting after the configuration has been completed will make it easier to observe the 802.1X behavior). For my lab, I used a Windows XP box with SP2.

To enable the Windows 802.1X service, open Services from the control panel, and select and start the Wireless Zero Configuration service. (“But isn’t this a wired connection?” I hear you ask. Thank you, Microsoft.) (Edit: Wired 802.1X is enabled by a separate service, Wired AutoConfig, in XP SP3. Thanks to Dude for pointing this out!) Next, open Network Connections from the control panel and open the Connection Properties dialog for the adapter you’re using. You should have an Authentication tab within this window; if not, the 802.1X service isn’t running and you’ll need to do some troubleshooting.

Enable 802.1X authentication and set the EAP type to MD5-Challenge. This will allow us to use basic username/password credentials instead of a more secure (and much more complex) PKI scheme. You can safely deselect the “authenticate as computer” and “authenticate as guest” options.
Authenticating

If everything is configured correctly, you should now be able to authenticate via 802.1X. Verify your IP addressing and connect your client to the switch. After roughly thirty seconds you should be prompted for authentication credentials by a little balloon. (In a more ideal setup, your Windows credentials and/or a client certificate would be sent without your interaction and 802.1X authentication would occur transparently.) Your prompt may differ from the example shown here.

Enter the username and password you configured on the RADIUS server in the authentication dialog.

Your client will notify you after a bit if the authentication fails. If you receive no notification, authentication has succeeded and you should be able to send traffic through the switch port (try pinging through to the RADIUS server to verify this). Issue the show dot1x command on the switch again to verify that the port is now in the “authorized” state.

Switch# show dot1x interface g0/12
Supplicant MAC 0014.22e9.545e
AuthSM State = AUTHENTICATED
BendSM State = IDLE
PortStatus = AUTHORIZED
MaxReq = 2
MaxAuthReq = 2
HostMode = Single
PortControl = Auto
QuietPeriod = 60 Seconds
Re-authentication = Disabled
ReAuthPeriod = 3600 Seconds
ServerTimeout = 30 Seconds
SuppTimeout = 30 Seconds
TxPeriod = 30 Seconds
Guest-Vlan = 0

One other detail to note: Initially, the client’s port on the switch will only transition to up/down (interface up, line protocol down) when you first connect. Only after successfully authenticating via 802.1X will it transition fully to up/up.

If authentication fails for some reason you’ll have to do some sleuthing to determine the cause. Keep the following tips in mind:

Ensure that the switch is trying to authenticate to the correct RADIUS server on the correct UDP port
Ensure the RADIUS server is configured to accept authentication requests from the correct subnet
Review the RADIUS daemon logs for messages concerning failed authentication or misconfiguration
Use a variation of the debug dot1x command on the switch or a packet sniffer to verify EAP and RADIUS traffic
Try using the free NTRadPing RADIUS Test Utility to independently verify operation of the RADIUS server

The files in C:\windows\system32\config folder are the registry hive files (All Windows information are stored in Registry). Corrupted or Missing registry files – system, software, security, default, sam will cause boot failure.

Copies of these files are saved in C:\windows\repair folder after successful installation of Windows. In case of disaster, these files can be copied from c:\windows\repair folder to c:\windows\system32\config folder.

NB: Copy only the file, which is notified as missing or corrupt. It will take your setting back to the freshly installed position.

Recovery Console can be used to copy the backup files

To complete part one, follow these steps:

1. Insert Windows XP CD-ROM into the CD-ROM drive, and then restart the computer.
Click to select any options that are required to start the computer from the CD-ROM drive if you are prompted to do so.
2. When the “Welcome to Setup” screen appears, press R to start the Recovery Console.
3. If you have a dual-boot or multiple-boot computer, select the installation that you want to access from the Recovery Console.
4. When you are prompted to do so, type the Administrator password. If the administrator password is blank, just press ENTER.
5. At the Recovery Console command prompt, type the following lines, pressing ENTER after you type each line:

md tmp
copy c:\windows\system32\config\system c:\windows\tmp\system.bak
copy c:\windows\system32\config\software c:\windows\tmp\software.bak
copy c:\windows\system32\config\sam c:\windows\tmp\sam.bak
copy c:\windows\system32\config\security c:\windows\tmp\security.bak
copy c:\windows\system32\config\default c:\windows\tmp\default.bak

delete c:\windows\system32\config\system
delete c:\windows\system32\config\software
delete c:\windows\system32\config\sam
delete c:\windows\system32\config\security
delete c:\windows\system32\config\default

copy c:\windows\repair\system c:\windows\system32\config\system
copy c:\windows\repair\software c:\windows\system32\config\software
copy c:\windows\repair\sam c:\windows\system32\config\sam
copy c:\windows\repair\security c:\windows\system32\config\security
copy c:\windows\repair\default c:\windows\system32\config\default

6. Type exit to quit Recovery Console. Your computer will restart.

The files in C:\windows\system32\config folder are the registry hive files (All Windows information are stored in Registry). Corrupted or Missing registry files – system, software, security, default, sam will cause boot failure.

Copies of these files are saved in C:\windows\repair folder after successful installation of Windows. In case of disaster, these files can be copied from c:\windows\repair folder to c:\windows\system32\config folder.

NB: Copy only the file, which is notified as missing or corrupt. It will take your setting back to the freshly installed position.

Recovery Console can be used to copy the backup files

To complete part one, follow these steps:

1. Insert Windows XP CD-ROM into the CD-ROM drive, and then restart the computer.
Click to select any options that are required to start the computer from the CD-ROM drive if you are prompted to do so.
2. When the “Welcome to Setup” screen appears, press R to start the Recovery Console.
3. If you have a dual-boot or multiple-boot computer, select the installation that you want to access from the Recovery Console.
4. When you are prompted to do so, type the Administrator password. If the administrator password is blank, just press ENTER.
5. At the Recovery Console command prompt, type the following lines, pressing ENTER after you type each line:

md tmp
copy c:\windows\system32\config\system c:\windows\tmp\system.bak
copy c:\windows\system32\config\software c:\windows\tmp\software.bak
copy c:\windows\system32\config\sam c:\windows\tmp\sam.bak
copy c:\windows\system32\config\security c:\windows\tmp\security.bak
copy c:\windows\system32\config\default c:\windows\tmp\default.bak

delete c:\windows\system32\config\system
delete c:\windows\system32\config\software
delete c:\windows\system32\config\sam
delete c:\windows\system32\config\security
delete c:\windows\system32\config\default

copy c:\windows\repair\system c:\windows\system32\config\system
copy c:\windows\repair\software c:\windows\system32\config\software
copy c:\windows\repair\sam c:\windows\system32\config\sam
copy c:\windows\repair\security c:\windows\system32\config\security
copy c:\windows\repair\default c:\windows\system32\config\default

6. Type exit to quit Recovery Console. Your computer will restart.

This file can be extracted from Windows XP/2003 CD using Recovery Console.

1. Boot from Windows XP CD
2. Enter Recovery Console
3. Extract file

c:\windows> expand e:\i386\hal.dl_ c:\windows\system32\hal.dll

1. Exit and reboot computer

The problem can occur if the Default value in the [Boot Loader] section of the Boot.ini file is missing or invalid.

Use the Bootcfg utility in the Recovery Console to correct the Boot.ini file:

1. Use the Windows XP CD-ROM to start your computer.
2. When you receive the message to press R to repair Windows by using the Recovery Console, press the R key.
3. Select the Windows installation that you want, and then type the administrator password when prompted.
4. Type bootcfg /rebuild, and then press ENTER.
5. When the Windows installation is located, the following instructions are displayed:

Add installation to boot list? (Yes/No/All)
[Type Y in response to this message.]

Enter Load Identifier:
[This is the name of the operating system. Type Windows XP Professional orWindows XP Home Edition.]

Enter OS Load options:
[Leave this field blank, and then press ENTER].

After you perform the preceding steps, restart the computer, and then select the first item on the boot menu. This should allow Windows XP to start normally.

After Windows XP has successfully loaded, the Boot.ini can be modified to remove the incorrect entry.

I am creating a birthday calendar of all my friends and family. Can you please click on the link below to enter your birthday for me?

http://www.birthdayalarm.com/bd2/85461055a62724071b1475231304c670697033d1386

Thanks,
Manoj

so that it starts up everytime you turn on your computer. just go to this key and add the whole path:

hkml\software\microsoft\windows\currentversion\run

create a string value and name it whatever you want, then double click on it and type the whole path for the batch file. i don;t know if this helps, but hey that is what i do when i want programs to run “such as netcat” when the person turns on his computer lol

1. Click Start, and then click Run.

2. In Open box, type rsop.msc, and then click OK. Back to the top How to Start RSoP As an MMC Snap-in 1. Start Microsoft Management Console (MMC), click Start, click Run, type mmc, and then click OK. 2. On the File menu, click Add/Remove Snap-in.

3. On the Standalone tab, click Add.

4. In the Available Standalone Snap-in box, click Resultant Set of Policy, and then click Add.

NOTE: You must add a RSoP snap-in to MMC for each new RSoP query. Back to the top How to Access RSoP Data for an Existing Computer and User in Logging Mode

1. In the RSoP snap-in, right-click Resultant Set of Policy, and then click Generate RSoP Data.

2. After the RSoP Wizard starts, click Next.

3. Click Logging mode, and then click Next.

4. Specify the computer on which you want to run RSoP, and then click Next.

5. Specify the user for which you want to collect RSoP data, and then click Next.

6. Review the summary of settings, click Next, and then wait for RSoP to finish processing the data.

7. Click Finish.

8. In the RSoP snap-in, click the newly created RSoP query in the console tree to view the data.

NOTE: Only users and computers that are currently logged on to the domain are visible. Back to the top How to Save Data from an RSoP Query

1. Open an RSoP query in the RSoP snap-in.

2. In the console tree, click Console Root, and then double-click User account on computer account – RSoP in the right pane.

3. On the View menu, click Archive data in console file.

4. On the File menu, click Save.

5. In the File name box, type a name for the file, and then click Save. Back to the top How to Change an Existing RSoP Query

1. In the RSoP snap-in, right-click the RSoP query that you want to change, and then click Change Query.

2. After the RSoP Wizard starts, click Next to select the appropriate step for the query option that you want to change.

3. Click Finish. Back to the top How to Refresh an RSoP Query In the RSoP snap-in, right-click the RSoP query that you want to refresh, and then click Refresh Query. Back to the top How to View an RSoP Report in HTML

1. Click Start, and then click Help and Support.

2. Under Support Tasks, click Tools.

3. Under Tools, click Advanced System Information.

4. Under Advanced System Information, click View Group Policy settings applied.

5. Scroll to the results that you want to view.

NOTE: To hide details, click the arrow in the upper-right corner of a category. Back to the top How to Run an RSoP Query on a Computer Account

1. Click Start, click Control Panel, double-click Administrative Tools, and then double-click Active Directory Users and Computers.

2. In the console tree, expand Domain (where Domain is the domain in which the computer account on which you want to run RSoP exists), and then expand Computers.

3. Right-click the computer account on which you want to run RSoP, point to All Tasks, and then click Resultant Set of Policy (Logging) or Resultant Set of Policy (Planning).

NOTE: You can also run an RSoP query by adding the RSoP snap-in to an MMC. Back to the top How to Run an RSoP Query on a User Account

1. Click Start, click Control Panel, double-click Administrative Tools, and then double-click Active Directory Users and Computers.

2. In the console tree, expand Domain (where Domain is the domain in which the user account on which you want to run RSoP exists), and then expand Users.

3. Right-click the user account on which you want to run RSoP, point to All Tasks, and then click either Resultant Set of Policy (Logging) or Resultant Set of Policy (Planning). Back to the top How to Run an RSoP Query on a Domain

1. Click Start, click Control Panel, double-click Administrative Tools, and then double-click Active Directory Users and Computers.

2. In the console tree, expand Active Directory Users and Computers, expand Domains, and then right-click the domain on which you want to run RSoP.

3. Point to All Tasks, and then click Resultant Set of Policy (Planning). Back to the top How to Run an RSoP Query on an Organizational Unit

1. Click Start, click Control Panel, double-click Administrative Tools, and then double-click Active Directory Users and Computers.

2. In the console tree, expand Active Directory Users and Computers, expand Domain, expand Organizational unit, and then expand child organizational unit.

3. Right-click the organizational unit on which you want to run RSoP, point to All Tasks, and then click Resultant Set of Policy (Planning). Back to the top How to Run an RSoP Query on a Site

1. Click Start, point to All Programs, point to Administrative Tools, and then click Active Directory Sites and Services.

2. In the console tree, expand Active Directory Sites and Services, and then expand Sites.

3. Right-click the site on which you want to run RSoP, point to All Tasks, and then click Resultant Set of Policy (Planning).

NOTE: If you use this method to open RSoP, you cannot change the site name in the RSoP query. You can also run an RSoP query by adding the RSoP snap-in to an MMC. Back to the top How to Run an RSoP Query on a Local Computer

1. Click Start, click Run, type mmc, and then click OK.

2. On the File menu, click Add/Remove Snap-in.

3. Click the Standalone tab, and then click Add.

4. In the Available Standalone Snap-in box, click Resultant Set of Policy, and then click Add.

5. In MMC, right-click Resultant Set of Policy, and then click Generate RSoP Data.

6. After the Resultant Set of Policy Wizard starts, click Next. 7. Click Logging mode, and then click Next.